Module footprintjs/sinks

Node only. The crash-safe record as a JSON-lines file.

This door imports node:fs; it is the one door that does (test/architecture/layering.test.ts), so every other door stays loadable in a browser. The port itself — RecordSink, and the reference memorySink() — is foottrace's (foottrace/write); the reader is readStoredRecord (foottrace).

Example

import { flowChart, FlowChartExecutor } from 'footprintjs';
import { fileSink, readRecordFile } from 'footprintjs/sinks';
import { readStoredRecord } from 'foottrace';

const executor = new FlowChartExecutor(chart, { sink: fileSink('/var/footprint/orders.jsonl') });
await executor.run({ input });

// After a crash — in another process:
const record = readStoredRecord(readRecordFile('/var/footprint/orders.jsonl').entries);
for (const log of record.logs.values()) if (!log.complete) console.log('never finished:', log.address);

Interfaces

FileSink: A record sink that appends to one file — RecordSink plus what the app needs to manage the file.
FileSinkOptions: fileSink's options — every resource the sink can spend, bounded.
IndexedRecordFile: One immutable-file selection capability. No path, descriptor, mutable index or discovered run catalog is served.
IndexedRecordFileOptions: Host authorization is fixed before any stored entry is read. It is never inferred from the index.
IndexedRecordScope
IndexedRecordUnknown
RecordFile: A record file read back: every parsed line, and every line that could not be.

Type Aliases

IndexedRecordFileReason
IndexedRecordFileResult

Variables

DEFAULT_FILE_SINK_FLUSH_TIMEOUT_MS: The default bound on flush(): 10 s.
DEFAULT_FILE_SINK_MAX_BYTES: The default cap on a record file: 64 MiB.
DEFAULT_FILE_SINK_MAX_ENTRY_BYTES: The default cap on ONE entry's line: 8 MiB.
DEFAULT_FILE_SINK_MAX_QUEUED_BYTES: The default cap on bytes accepted but not yet written: 16 MiB.

Functions

fileSink: A record sink that appends each entry to path as one JSON line — the crash-safe record on a Node host.
openIndexedRecordFile: Explicit bounded whole-file preparation, followed by authorized positional scope reads from that immutable file.
readRecordFile: Read a record file back, line by line — the entries for readStoredRecord, and every line that could not be read, by number, never a failed read. A stored key named __proto__ stays data (JSON.parse makes it an own property). The file is untrusted: a file larger than maxBytes (default 256 MiB) is refused before it is read.